Answer:
in this scenario a color change occured.
Do all irreversible reactions go to completion? If so why?
Answer:
True
Explanation:
All irreversible reactions go to completion because the process cannot proceed in the backward direction.
A reversible reaction is one that does not go into completion in one direction.
An irreversible direction completely uses up the reactants to form the products and goes into completion.
These reactions can only proceed in one direction and not both.
Strontium-90 is one of the products of the fission of uranium-235. This strontium isotope is radioactive, with a half-life of 28.1 yr. Calculate how long it will take for 0.900 g of the isotope to be reduced to 0.170 g by decay.
Answer:
67.6 years is the time the isotope take to decay from 0.900g to 0.170g
Explanation:
The radioactive decay follows first order law:
Ln [A] = -kt + ln[A]₀
Where [A] is concentration after time t,
k is decay constant:
k = ln 2 / t(1/2)
k = ln2 / 28.1 years
k = 0.02467 years⁻¹
[A]₀ = Initial concentration.
We can replace concentration and use the mass of the isotope:
Ln [A] = -kt + ln[A]₀
Ln [0.170g] = -0.02467 years⁻¹t + ln[0.900g]
-1.667 = -0.02467 years⁻¹t
t =
67.6 years is the time the isotope take to decay from 0.900g to 0.170gThe time required for the sample to reduce to 0.170 grams has been 67.75 years.
Half-life can be defined as the times required by the substance to reduce to half of its initial concentration.
The half-life can be expressed as:
Amount left = Initial amount [tex]\times[/tex] [tex]\rm \dfrac{1}{2}^\dfrac{time}{Half-life}[/tex]
From the given:
0.17 g = 0.9 [tex]\rm \times\;\dfrac{1}{2}^\dfrac{t}{28.1}[/tex]
[tex]\rm \dfrac{0.17}{0.9}[/tex] = [tex]\rm \dfrac{1}{2}^\dfrac{t}{28.1}[/tex]
0.188 = [tex]\rm (0.5)^\dfrac{t}{28.1}[/tex]
Taking log on both the sides,
log 0.188 = [tex]\rm \dfrac{t}{28.1}\;\times[/tex] log 0.5
2.411 = [tex]\rm\dfrac{t}{28.1}[/tex]
t = 2.411 [tex]\times[/tex] 28.1 years
Time = 67.75 years.
The time required for the sample to reduce to 0.170 grams has been 67.75 years.
For more information about half-life, refer to the link:
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ANSWER THIS TO BE MARKED BRAINILEST Water in a beaker measures 250 milliliters. A rock is completely submerged in the water. The water level now reads 375 milliliters. What is the volume of the rock in cubic centimeters? Explain your answer
Answer:
125 cubic meters
Explanation:
Subtract 375-250=125 cubic meters
In the reaction 2Li(s) + 2H20(1) 2LIOH(aq) + H2(g), which compound is in
the liquid state?
A. H20
B. LiOH
C. Li
O D. H2
Answer:
liquid state is an intermediate phase between solid and gas phase
Answer is A. H20
Answer:
H2O
Explanation:
As H2 is a gas, and the question asks for the liquid state, it'd be H2O.
When an object resist movement by a force
Answer: Inertia
Explanation:
Marissa blows up balloons for a party. She decides how big or small to make each balloon. Why does the air she blows into each balloon take up all the space inside the balloon
The density of ice at its freezing point is 0.917 g/cm3. What is the mass of 2.5 cm3 of ice at this temperature?
A. 1.6 g
B. 2.3 g
C.2.7 g
D.3.4 g
Answer:
The answer is option BExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volume
From the question we have
mass = 0.917 × 2.5 = 2.2925
We have the final answer as
2.3 gHope this helps you
Answer:. 2.3 g
Explanation:
Is buoyancy a physical or chemical property?
Students measuring the mass of a metal block record 2.985 g, 3.051 g, 3.102
g, and 3.211 g. Which other measurement of the block's mass would be most
precise?
A. 2.804 g
B. 3.1159
C. 3.418 g
D. 3.509 g
Answer:C - 3.115 g
Explanation:Correct
Which of the following best illustrates the law of corkervation of energy?
A
The work done stretching a spring is transformed into stored energy in the spring
B
Leak-proof batteries are able to store chemical energy for long periods of time.
С
Ajogger conserves her energy by reducing the rate at which she jogs.
D
Ice water changes into liquid water when it absorbs heat energy.
Answer:
A . The work done stretching a spring is transformed into stored energy in the spring
Explanation:
The work done stretching a spring is transformed into stored energy in the spring is clear indication of the law of conservation of energy.
The law of conservation of energy states that "energy is neither created nor destroyed but transformed from one form to another".
In this problem, mechanical energy is used to stretch the spring. The mechanical energy is converted to stored potential energy.This is an energy transformation process.
How do you differentiate a neutral solution like water and a strong acid solution like battery acid?
Answer:
If the pH of a solution is less than 7, the solution is called acidic; if the pH is about 7, the solution is neutral; if the pH is greater than 7, the solution is is called basic. In an acidic solution, then, the concentration of hydrogen ions is greater than the concentration of hydroxide ions.
Explanation:
Not sure about the context of the question, but you can check with a ph scale tester.
Fill in the coefficients that will balance the following reaction:
(Note: Use 1 as coefficient where appropriate.)
CH4 +
O2 →
CO2 +
H2O
Answer:
CH4 + 2 O2 → CO2 + 2 H2O
Explanation:
There are one mole of O2 on the left side and on the right side there are three moles of O2. And to fix it you would need to make it two moles of O2 to have four molecules of O2 on the left side. Then you would make two moles of H2O to have a total of four moles of O2 on the right. Therefore, CH4 + 2 O2 → CO2 + 2 H2O is the answer.
Answer:
1,2,1,2
Explanation:
hope this helped!
A student used the Dumas method to determine the molar mass of a volatile material. They placed the container into the ice bath BEFORE all of the material was vaporized. What will happen to their final calculations?
A. The Molar Mass will be too low.
B. The Molar Mass will not be effected.
C. The Molar Mass will be too high.
Answer: the molar mass will be too high
Explanation:
please I need help with everything
Answer:
See below!
Explanation:
An acid (A) will have acid in the name. It will also have a hydrogen bonded to an electronegative compound. A molecular compound (M) will have nonmetals and/or hydrogen. An ionic compound (I) will have nonmetals and first and second column metals. It could also include charged compounds. A transition metal (TM) will have a transition metal in the compound.
The formulas for TM and I are made by balancing the charges of the atoms to equal zero. The formulas for M can be found from the name itself. The formulas for A have to be memorized.
TM ==> copper (II) oxide ==> CuO
A ==> hydrosulfuric acid ==> H₂S
TM ==> iron (III) fluoride ==> FeF₃
TM ==> lead (II) chlorate ==> PbCl₂
A ==> hydrochloric acid ==> HCl
M ==> dihydrogen monoxide ==> H₂O
A ==> sulfurous acid ==> H₂SO₃
I ==> potassium oxide ==> KO
I ==> ammonium hydroxide ==> NH₄OH
M ==> nitrogen trioxide ==> NO₃
I ==> aluminum phosphate ==> AlPO₄
To name ionic (I) compounds, simply put the name of the metal with the nonmetal. But, for the nonmetal change, the ending to "-ide". To name acids (A), say hydro- with the atom/compound it is attached to and end with acid.
I ==> MgSO₄ ==> magnesium sulfate
I ==> HgS ==> mercury sulfide
I ==> Na₂S ==> sodium sulfide
A ==> HF ==> hydrofluoric acid
I ==> KCN ==> potassium cyanide
When mixing an acid with water, which of the following must always be done?
A.
Never mix an acid with water, it will explode.
B.
Always add the acid to the water slowly, taking a moment to stir between drops.
C.
Always heat the acid before mixing with water.
D.
Always shake both solutions before mixing.
Answer:
B
Explanation:
Answer:
B. Always add the acid to the water slowly, taking a moment to stir between drops
2Ni(OH) → Ni2O + H2O
How many moles of water forms from 4.20 mol of nickel (I) hydroxide?
Answer:
2.1 moles of water formed.
Explanation:
Given data:
Moles of water formed = ?
Moles of Ni(OH) = 4.20 mol
Solution:
Chemical equation:
2Ni(OH) → Ni₂O + H₂O
Now we will compare the moles of Ni(OH) with water.
Ni(OH) : H₂O
2 : 1
4.20 : 1/2×4.20 = 2.1 mol
2.1 moles of water formed.
can someone please help me i don't know these question bc my family celebrates thanksgiving differently. plz and thank you :3
Easy: How many turkeys are consumed on Thanksgiving day in America?
Medium: How long did the first Thanksgiving Celebration last?
Hard: When was the first NFL football game on Thanksgiving?
Fun: Who was the first president to pardon a turkey?
Answer:
Easy 46 million turkeys
Medium three days
Hard: 1934
Fun: The first President on record issuing a "pardon" to his turkey was Ronald Reagan.
Explanation:
hop tis helped
what are all the ways you can change a piece of binder paper?
Answer:
you can burn it.
Explanation:
that is the way to change paper
Group 17 is called the halogen family, and the group to its right is called the noble gases. How are these elements alike and how are they different?
Explanation:
The halogen family and noble gases are similar in just one particular way, they are groups of non-metals. All members of these two groups are categorized as non-metals.
Here are some of the differences between them;
Halogens have 7 electrons in their outermost shell whereas noble gases have 8 electrons in theirs. Halogens are highly reactive elements, noble gases are non-reactive. Halogens are made up of electronegative elements where as noble gases are neither electropositive nor electronegative.does boron or lithium have a greater first ionization energy ?
Answer:
beryllium has a higher ionization energy because its radius is smaller. boron has a higher ionization energy because its radius is smaller.
what is the volume of 5 moles of oxygen gas at rtp
Answer:
5 moles of oxygen occupy 120 dm³ volume.
Explanation:
Given data:
Number of moles = 5 mol
Volume of gas = ?
Solution:
In question it is given gas is at room temperature and pressure.
One mole of any gas at room room temperature and pressure occupy volume of 24 dm³. Thus,
5 mole of gas occupy volume of,
5 mol × 24 dm³/1 mol
120 dm³
5 moles of oxygen occupy 120 dm³ volume.
What is the independent variable when testing to see how the viscosity of a liquid affects its flow rate
Answer:
Viscosity
Explanation:
The viscosity of the liquid is the independent variable. The flow rate is the dependent variable in this hypothesis.
The statement given is called the hypothesis. It is a form of scientific guess into a phenomenon.
An independent variable is the cause. A dependent variable is the effect produced. In this hypothesis, the cause of the various flow rate of the liquid is the viscosity. It is therefore the independent variable. The flow rate is the dependent variable.The combination of all the organ systems working together make up a(n) _______________________.
1.organ system
2.organism
3.organ
4.cell
Answer:
2
Explanation:
Please give formulas of how you solved I only need help on a but if you can do all that I would appreciate that.
Answer:
3.1 moles of ammonia
18.67× 10²³ molecules
Mass = 52.7 g
Explanation:
Given data:
Number of atoms of hydrogen = 5.68×10²⁴ atoms
A) Number of molecules of ammonia = ?
Solution:
First of all we will calculate the number of moles of hydrogen.
1 mole = 6.022× 10²³ atoms
5.68×10²⁴ atoms × 1 mol / 6.022× 10²³ atoms
0.94×10¹ mol
9.4 moles of hydrogen
Moles of ammonia:
3 moles of hydrogen are present in one mole of ammonia.
9.4 moles of hydrogen = 1/3×9.4 =
3.1 moles of ammonia
Number of molecules of ammonia:
1 mole contain 6.022× 10²³ molecules.
3.1 mol × 6.022× 10²³ molecules / 1 mol
18.67× 10²³ molecules
c) Mass of sample = ?
Mass = number of moles × molar mass
Mass = 3.1 moles × 17 g/mol
Mass = 52.7 g
Where is type of precipitation is most likely to form during a thunderstorm
Answer:
hail, btw have a nice day
Answer:
Hail
Explanation:
I got it right on my test
help please this is due soon!!
Answer:
33
Explanation:
Whats faster light or sound? PLEASE HELPY ME
Answer:
The answer is that light is faster than sound.
Explanation:
A good example is of lightning and thunder during a thunderstorm.
mark me brainliest!
The Texas high plains region does not revive much rain. It is reasonable to predict that this region, compared to other ecoregions, would have
Answer:
Less soil erosion
Explanation:
Due to the low amount of rainfall in this region, it is easier to say that the region compared to other ecoregion will suffer less soil erosion.
Erosion is usually the washing away of the top layer of the soil. Rainfall is one of the most important element that causes erosion. Surface runoff for an extended period of time can remove the topmost layer of the earth on which plant can grow. This starves the soil of its rich nutrients and minerals.
Describe the levels of organization of a complex, multicellur organism such as a mouse starting with the cell
The level of organization of a complex, multicellular organism such as a mouse, starting with the cell, is. The cellular level, the tissue level, the organ level, the organ system, and lastly the organism.
What is level or organization?The level of organization of the body is the organization of the body with the smallest unit like the cell. As we know, the smallest unit of life is the cell. So the organization of energy in living organisms starts with a cell.
The cellular level is the cells, the cell combine to form tissue and many tissues join together to form an organ. Many organs join together to create an organ system, and the organ system establishes an organism.
Thus, starting with the cell, the organization of a complex, multicellular creature like a mouse is. cell level, tissue level, organ level, the organ system, and finally organism level.
To learn more about level or organization, refer to the link:
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which of the following would form an ionic bond?
a.strontium and oxygen
b. sulfur and oxygen